So in my case I ran in debug mode. When I get slow startup, I see all the startup delay is accompanied by spewage of error messages claiming access errors in .caltrash - and it simply takes time to get through all the entries. HOWEVER, . I will note that I've storage my library on OneDrive for (at least) four years w/o issue, so to me this isn't obviously a case of "you can't store on OneDrive" and I'll be suspicious of any workaround that implies this w/o also explaining why it has always worked up until sometime in the last 90 days.
Nevertheless, I'll try excluding my AV from looking at .caltrash to see if there's a relationship. I also note that the folders in .caltrash are all empty - which I'd expect, because I typically use the GUI to empty the trash. So I might, at some point, manually delete the contents of .caltrash to see if that also prevents long startup.
Traceback (most recent call last):
File "calibre\db\backend.py", line 449, in rmtree_with_retry
File "shutil.py", line 787, in rmtree
File "shutil.py", line 638, in _rmtree_unsafe
File "shutil.py", line 636, in _rmtree_unsafe
PermissionError: [WinError 5] Access is denied: 'C:\\Users\\dstei\\OneDrive\\Books-CalibreLibrary\\.caltrash\\b\\2295'
During handling of the above exception, another exception occurred:
Spoiler:
Traceback (most recent call last):
File "calibre\db\backend.py", line 2243, in expire_old_trash
File "calibre\db\backend.py", line 455, in rmtree_with_retry
File "shutil.py", line 787, in rmtree
File "shutil.py", line 638, in _rmtree_unsafe
File "shutil.py", line 636, in _rmtree_unsafe
PermissionError: [WinError 5] Access is denied: 'C:\\Users\\dstei\\OneDrive\\Books-CalibreLibrary\\.caltrash\\b\\2295'
Traceback (most recent call last):
File "calibre\db\backend.py", line 449, in rmtree_with_retry
File "shutil.py", line 787, in rmtree
File "shutil.py", line 638, in _rmtree_unsafe
File "shutil.py", line 636, in _rmtree_unsafe
PermissionError: [WinError 5] Access is denied: 'C:\\Users\\dstei\\OneDrive\\Books-CalibreLibrary\\.caltrash\\b\\2298'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "calibre\db\backend.py", line 2243, in expire_old_trash
File "calibre\db\backend.py", line 455, in rmtree_with_retry
File "shutil.py", line 787, in rmtree
File "shutil.py", line 638, in _rmtree_unsafe
File "shutil.py", line 636, in _rmtree_unsafe
PermissionError: [WinError 5] Access is denied: 'C:\\Users\\dstei\\OneDrive\\Books-CalibreLibrary\\.caltrash\\b\\2298'
Traceback (most recent call last):
File "calibre\db\backend.py", line 449, in rmtree_with_retry
File "shutil.py", line 787, in rmtree
File "shutil.py", line 638, in _rmtree_unsafe
File "shutil.py", line 636, in _rmtree_unsafe
PermissionError: [WinError 5] Access is denied: 'C:\\Users\\dstei\\OneDrive\\Books-CalibreLibrary\\.caltrash\\b\\2304'